Series arc detection in low voltage distribution switchboard using spectral analysis

In switchboards, a conduction fault almost always degenerates into a series arc, then into a parallel arc. A study performed by P. Gastaldello in 1998 showed that series arcs naturally emit ultrasonic waves into the busbar. In this paper a new method is proposed to detect series fault arcs, characterizing and modeling its acoustic emission. The envelope of the signal has been computed. Then three criteria based on spectral analysis and signal energy and waveform have been adjusted to differentiate the fault arc from all the other sounds conducted by the busbar. The approach has been evaluated on a large database of real signals. Its reliability is linked to the length of detection. Its robustness is provided by the association of the three above mentioned criteria. A prototype has been developed to validate the approach